Scanning probe microscopy probes and methods

ABSTRACT

A method for fabricating scanning probe microscopy (SPM) probes is disclosed. The probes are fabricated by forming a structural layer on a substrate, wherein the substrate forms a cavity. A sacrificial layer is located between the substrate and the structural layer. Upon forming the structural layer, the sacrificial layer is selectively removed, and the probe is then released from the substrate. The substrate may then later be reused to form additional probes. Additionally, a contact printing method using a scanning probe microscopy probe is also disclosed.

RELATED APPLICATION DATA

The present application is a divisional of U.S. application Ser. No.10/440,022, filed May 16, 2003, which is incorporated herein byreference to the extent permitted by law.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with Government support under the NationalScience Foundation under the NSF Program (Grant No. 0118025), DARPAGrant No. DAAD-19-00-1-0414 and AFOSR Grant No. F49620-00-1-0283. Thegovernment may have certain rights in this invention.

BACKGROUND

This invention relates generally to scanning probe microscopy(hereinafter “SPM”), and in particular, to an SPM probe formed with anintegrated tip and to a method of printing with an SPM probe.

A scanning probe microscope is an important instrument for science andtechnology. One of the first scanning probe microscopes ever developedwas called a Scanning Tunneling Microscope (STM). Another device withinthe scanning probe microscope family is an Atomic Force Microscope(hereinafter “AFM”). Nowadays, scanning probe microscopes are used tomeasure surface properties with atomic resolution. For example, scanningprobe microscopes can be used to observe the structure of double helixof DNA. The capability of scanning probe microscopes has spread toinclude imaging of magnetic, optical, thermal, electrostatic charges,and many more. Scanning probe microscopes are also used for biologicalsensors as the static bending and resonant frequency of a scanning probemicroscope is sensitive to the biochemical substances absorbed on it.Scanning probe microscopes are also used to perform nanolithography,such as dip pen nanolithography, and nanomanipulation, that is,interacting with objects on a molecular and an atomic scale.

Scanning probe microscopes use a probe having a flexible cantilever beamwith a sharp tip attached at the distal end to perform theirmeasurements. The cantilever beam is very soft, often with a forceconstant on the order of 0.1 N/m or less. The tip is used to interactwith the surface of interest. In an AFM for example, the repulsive forcebetween the surface and the tip causes the cantilever beam to bend. Theminute amount of bending in the cantilever beam is picked up by usingsensitive instruments, such as by optical deflection. By raster scanningthe tip over a sample surface area, a local topological map can beproduced. If the tip of the probe is relatively sharp, the topologicalmap may be made with atomic resolution. Typically, the radius ofcurvature of tips range below 500 nanometers.

Needless to say, the SPM probe's cantilever beam with integrated tip isa performance limiting device in the overall scanning probe microscopesystem. Many research groups as well as companies that commercialize thescanning probe microscope spend much time to develop the cantilever beamand the tip of the probe. Using current fabrication methods, thecantilever beam is typically made of silicon nitride or single crystalsilicon while the tip is typically etched by bulk silicon etching usingwet etching chemicals or plasma etching. There are a number of majordrawbacks to existing fabrication methods. First, the tips are madesharp using a special, time-sensitive processes that is not veryefficient. Additionally, it is difficult to produce large arrays of tipswith uniform sharpness. Moreover, the cantilevers are made of inorganicthin films such as silicon nitride or single crystal silicon whichrequire a high temperature process and multiple process steps, such as abulk silicon etch, to produce. Furthermore, certain processes requireremoval of a substrate upon which the probes are fabricated upon inorder to remove the probe, and more specifically, the cantilever, fromthe substrate. Thus, a need exists for an improved method forfabricating an SPM probe.

Additionally, there is a need for an improved method for fabricating anSPM probe, including an array of SPM probes, using an efficient process,low cost materials, and a uniform profile. Such probes can then be usedin a variety of ways, such as, for SPM, chemical/bio sensing, andnanolithography such as DPN.

There is also a need for an improved method for microcontact printing.Microcontact printing (μCP) is a soft lithography method capable ofcreating micro-scale structures on a microscopic level. Microcontactprinting uses a stamp to transfer chemical or biological materials, alsoknown as “ink,” onto a solid substrate. Microcontact printing createsimpressions with the patterned stamp by placing the stamp near, or incontact with, the solid substrate. Microcontact printing does not formimages by dragging the stamp across the solid substrate. Repeatedcontact with the solid substrate can form dots, lines, curves, and othersuch shapes. The stamp can be made of a variety of materials, such asmetals, polymers, and elastomeric materials. One of the more commonlyused elastomeric materials is poly(dimethylsiloxane) (PDMS), which is aninert material that is compatible with many chemical and biologicalinks. Microcontact printing has been used to pattern self-assembledmonolayers of alkanethiols, proteins, chemical precursors, and otherbiological materials on a variety of substrates. Microcontact printinghas also been used to transfer chemical or biological materials (inks)onto a solid substrate. However, microcontact printing invariablyrequires a dedicated photolithography mask to produce inverse moldfeatures, and is limited with respect to multi-ink and alignmentregistration capabilities. Additionally, the production of the mask canbe relatively costly and time consuming, particularly whensub-micrometer features are desired. Moreover, for many applications,such as the generation of proteomic and gene chips, well aligned,sub-micrometer scale features made of many different inks are desirable.Thus, a need exists for a less costly and less time consuming method formicrocontact printing.

BRIEF SUMMARY

According to one aspect of the present invention, a method forfabricating a scanning probe microscope probe is provided. The methodincludes forming a structural layer on a substrate. The substrate formsa cavity. A sacrificial layer is located between the substrate and thestructural layer. In one embodiment, the method further includesselectively removing the sacrificial layer. In one embodiment, themethod further includes releasing the structural layer from thesubstrate.

According to another aspect of the present invention, a method forfabricating a scanning probe microscope probe is provided. The methodincludes forming a structural layer on a substrate. The structural layerhas a tip layer and a beam layer. The substrate forms a cavity and thetip layer is in the cavity. The beam layer is on the tip layer. Asacrificial layer is located between the substrate and the tip layer.The method further includes patterning the structural layer.

According to another aspect of the present invention, a scanning probemicroscope probe is provided. The probe includes a tip having a firstmaterial and a cantilever beam connected with the tip. The cantileverbeam includes a second material. The first material includes one of ametal, an oxide, and a polymer, and the second material includes one ofa metal, an oxide, and a polymer.

According to another aspect of the present invention, a method forcontact printing is provided. The method includes positioning a scanningprobe microscopy probe having a tip near a substrate, wherein ink istransferred from the tip to the substrate. The tip comprises a polymer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1D illustrate, in cross-section, process steps for thefabrication of an SPM probe, in accordance with one preferred embodimentof the invention.

FIGS. 2A-2E illustrate, in cross-section, process steps for thefabrication of an SPM probe, in accordance with one preferred embodimentof the invention.

FIGS. 2F-2G illustrate, in cross-section, process steps for thefabrication of an SPM probe, in accordance with one preferred embodimentof the invention.

FIG. 3A is a perspective view of a probe, in accordance with onepreferred embodiment of the invention.

FIG. 3B is a perspective view of a probe, in accordance with onepreferred embodiment of the invention.

FIG. 3C is a perspective view of a probe, in accordance with onepreferred embodiment of the invention.

FIG. 3D is a perspective view of a probe, in accordance with onepreferred embodiment of the invention.

FIG. 3E is a perspective view of a probe, in accordance with onepreferred embodiment of the invention.

FIGS. 4A-4D illustrate, in a side view, process steps for contactprinting with a scanning probe, in accordance with one preferredembodiment of the invention.

FIG. 5 is a top view of a pattern 68 formed using a scanning probecontact printing process, in accordance with one preferred embodiment ofthe invention.

FIG. 6 is a side view of an atomic force microscope (AFM) scanning headconnected with a probe, in accordance with one preferred embodiment ofthe invention.

FIGS. 7A-7C illustrate lateral force microscopy (LFM) images of arraysof pixels generated using a scanning probe contact printing process, inaccordance with one preferred embodiment of the invention.

FIG. 8 is a perspective view of a probe 27 having a flat top, inaccordance with one preferred embodiment of the invention.

FIG. 9 is a chart comparing the pixel diameter to the contact timebetween the tip and the substrate, in accordance with one preferredembodiment of the invention.

FIG. 10 illustrates a lateral force microscopy (LFM) image of twopatterns formed using a scanning probe contact printing process, inaccordance with one preferred embodiment of the invention.

FIGS. 11A-11D illustrate lateral force microscopy (LFM) images ofpatterns formed using a scanning probe contact printing process, inaccordance with one preferred embodiment of the invention.

It should be appreciated that for simplicity and clarity ofillustration, elements shown in the Figures have not necessarily beendrawn to scale. For example, the dimensions of some of the elements areexaggerated relative to each other for clarity. Further, whereconsidered appropriate, reference numerals have been repeated among theFigures to indicate corresponding elements.

DETAILED DESCRIPTION

The present invention describes a method for fabricating scanning probemicroscopy (SPM) probes. The probes are fabricated by forming astructural layer on a substrate, wherein the substrate forms a cavity. Asacrificial layer is located between the substrate and the structurallayer. Upon forming the structural layer, the sacrificial layer isselectively removed, and the probe is then released from the substrate.The substrate may then later be reused to form additional probes. Inthis manner, an SPM probe can be fabricated that has a well defined tip.Additionally, since the substrate can be reused, the materials cost forproducing the probe can be reduced. Moreover, the above-described methodfor fabricating a probe allows for a variety of materials to be used tomanufacture the probe.

Shown in FIGS. 3A-3D is a probe 27 suitable for use in a scanning probemicroscope. Please note that while FIGS. 1C-1D and FIG. 3, illustrateonly one probe 27, and FIGS. 2B-2E illustrate two probes 27, 29, anarray of scanning probe microscopy (SPM) probes may have tens or evenhundreds of thousands of probes 27. In some instances, arrays of SPMprobes may have between one-hundred and ten million probes 27. For thesake of clarity, these additional probes have been left out of FIGS.1C-1D, FIGS. 2B-2E, and FIGS. 3A-3D.

Probe 27 includes a tip 30 comprising a first material and a cantileverbeam 28 comprising a second material. In one embodiment, the firstmaterial and the second material are the same material, while in anotherembodiment, the first material and the second material are differentmaterials. Preferably, the first material and the second material eachcomprise a material selected from the group consisting of metals such aspermalloy, copper, tungsten, titanium, aluminum, silver, and gold;oxides such as silicon dioxide, silicon oxide, and silicon oxynitride;nitrides such as silicon nitride and titanium nitride; and polymers suchas poly(dimethylsiloxane) (PDMS), polyimide, parylene, and elastomerssuch as silicone and rubber. The first and second materials may beformed by chemical reaction with the substrate 20, for example byoxidation, or by coating, for example with chemical vapor deposition oroblique angle physical vapor deposition.

The tip 30 is connected with the cantilever beam 28. The tip 30 may takevarious forms and shapes, such as pyramidal, conical, wedge, and boxed.In one embodiment, the tip 30 takes a form having a base 40 at one endand a point 42 at another end opposed to the base 40, such as a pyramid,a wedge, and a cone. The width of the tip 30 at the base 40 is greaterthan the width of the tip 30 at the point 42, as illustrated in FIG. 3Aand FIG. 2E. In one embodiment, the tip 30 takes the form of a wedge, asillustrated in FIG. 2E, wherein the width of the tip 30 at the base 40is greater than the width of the tip 30 at the point 42, as illustratedin FIG. 2E. In one embodiment, the tip 30 takes the form of a pyramid,as illustrated in FIG. 3A. Preferably, the tip 30 has a height “H” ofdefined as the distance from the base 40 to the point 42, as illustratedin FIG. 3A. Preferably, the tip 30 has a radius of curvature “R” definedat the point 42, as illustrated in FIG. 3A. Preferably, the height “H”is between 1 and 100 microns and the radius of curvature “R” is lessthan 350 nanometers, more preferably less than 100 nanometers, and mostpreferably less than 50 nanometers at the point 42. The pyramidal shapeof tip 30 includes a plurality of surfaces that form a plurality ofedges 37 and 39, as illustrated in FIG. 3A. The surfaces 39 and 37 areformed at angles α and β, respectively, with respect to a line normal tothe connecting surface 44, as illustrated in FIG. 3A. Preferably, theangles α and β are between 10° and 75°. In one embodiment, the tip 30takes a form having a base 40 at one end and a flat top 54 at anopposing end, as illustrated in FIG. 3E. The flat top 54 allows for theproduction of larger pixels 66 than the point 42, in order to increasethroughput in applications where lower resolution is acceptable.Preferably, the flat top 54 has less surface area than the base 42.

In one embodiment, the tip 30 and the cantilever beam 28 are integrallyformed, as illustrated in FIG. 2E and FIG. 3B. In one embodiment, thetip 30 is flat and is integrally formed at one end of the cantileverbeam 28, as illustrated in FIG. 3B. In one embodiment, the tip 30 coatsat least one surface of the cantilever 28, as illustrated in FIG. 3C. Inanother embodiment, the tip 30 coats one end of the cantilever 28, asillustrated in FIG. 3D. In one embodiment, the tip 30 includes a flatsurface 90 upon which a pattern of ink 60 may be formed, as describedbelow and as illustrated in FIGS. 3B, 3C, 3D, 3E. The flat surface 90does not have to be exactly flat. The flat surface 90 is able to accepta plurality of inks 60 and a plurality of patterns are able to be formedupon the flat surface 90. The flat surface 90 comprises a material suchas photoresist; SU-8; metals such as permalloy, copper, tungsten,titanium, aluminum, silver, and gold; oxides such as silicon dioxide,silicon oxide, and silicon oxynitride; nitrides such as silicon nitrideand titanium nitride; and polymers such as poly(dimethylsiloxane)(PDMS), polyimide, parylene, and elastomers such as silicone and rubber.Preferably, the flat surface 90 comprises a polymer.

The cantilever beam 28 has a connecting surface 44 opposed to a mountingsurface 46. Preferably, the mounting surface 46 is connected with ahandle 134, as illustrated in FIG. 2E. In one embodiment, the mountingsurface 46 is connected with an adhesion island 132, as illustrated inFIG. 2E. Preferably, the cantilever beam 28 has a thickness “t”, definedas the distance between the connecting surface 44 and the mountingsurface 46, of between 1 and 10 microns, a length “l” of between 100 and1,000 microns, and a width “w” of between 10 and 500 microns. In oneembodiment, the probe 27 comprises individual actuators on thecantilever beam 28 for height adjustment of the probe 27.

Shown in FIGS. 1A-1D, in cross-section, are process steps for thefabrication of an SPM probe 27 in accordance with one preferredembodiment of the invention. As illustrated in FIG. 1A, a substrate 20is provided. Preferably, the substrate 20 comprises a single crystalsilicon substrate, however, the substrate 20 may comprise othermaterials. Preferably, the substrate 20 comprises a thickness of 50 to1000 microns, and more preferably, 300 to 500 microns. Preferably, thesubstrate 20 has a top surface 21 that has been previously processed andcleaned to remove debris and native oxides.

A cavity 22 is formed in the substrate 20, and more particularly, in thetop surface 21 of the substrate 20. Preferably, the cavity 22 is formedby etching a shape into the substrate 20, however other means forforming the cavity 22 may be used. In one embodiment, the cavity 22 isformed using anisotropic etching. Preferably, the cavity 22 is formed byetching the substrate 20 wherein the cavity is bound by at least threesurfaces that meet at a point. The size and shape of the cavity 22 maybe controlled by adjusting the size of a mask opening used to form thecavity 22, and the and the amount of time the for the etching of thecavity 22. In one embodiment, the cavity 22 forms a sharp point at thebottom of the cavity 22, resulting in a tip 30 with a point 42. While inanother embodiment, the bottom of the cavity 22 is flat, resulting in atip 30 with a flat top 54, as illustrated in FIG. 3E. Preferably, thesubstrate 20 is first oxidized and patterned followed by anisotropic wetsilicon etching in ethylene diamine pyrocatechol (EDP) to form theinverted cavity 22. EDP may be obtained from Transene Company (Danvers,Mass.). If the etching time is sufficiently long, the resulting cavity22 is bound by four silicon surfaces and will end at a sharp point. Forshorter etching durations, a flat bottom of varying sizes may be formed.The cavity 22 serves as a mold to create the tip 30 of the probe 27, asdescribed below. By adjusting the size of the mask opening and the wetsilicon etching time, the shape of the bottom of the cavity 22 can becontrolled. If the cavity 22 ends in a sharp point, then a sharp tip 30having a point 42 forms, as illustrated in FIG. 3A. However, if thecavity 22 ends in a flat bottom, then a tip 30 with a flat top 54 forms,as illustrated in FIG. 3E. Tips 30 with a flat top 54 can be used toproduce larger pixels 66 to increase throughput in applications wherelower resolution is acceptable. The shape of the cavity 22 forms a threedimensional geometry that is opposite the desired shape of the tip 30.The cavity 22 serves as a mold for the tip 30 of the probe 27, asdescribed below. Preferably, the cross-sectional area of the cavity 22,taken along a line that is generally parallel with the top surface 21,is greater near the opening of the cavity 22 than at the bottom of thecavity 22, where the point 42 of the tip 30 is formed.

Upon forming the cavity 22, a sacrificial layer 24 is formed on thesubstrate 20, as illustrated in FIG. 1B. The sacrificial layer 24 may beformed by chemical reaction with the substrate 20, for example byoxidation, or by coating, for example with chemical vapor deposition oroblique angle physical vapor deposition. The sacrificial layer 24 isdifferent from the material contained in the substrate 20. Multiplematerials may also be used to form the sacrificial layer 24. In oneembodiment, the sacrificial layer 24 comprises at least one of manytypes of materials such as photoresist; SU-8; metals such as permalloy,copper, tungsten, titanium, aluminum, silver, and gold; oxides such assilicon dioxide, silicon oxide, and silicon oxynitride; nitrides such assilicon nitride and titanium nitride; and polymers such aspoly(dimethylsiloxane) (PDMS), polyimide, parylene, and elastomers suchas silicone and rubber. Preferably, the sacrificial layer comprisesaluminum, such as aluminum (99.999%) which may be obtained from AlfaAesar (Ward Hill, Mass.). The thickness of the sacrificial layer 24 mayvary, however, preferably, the thickness of the sacrificial layer 24 isbetween 1 and 100 microns, and more preferably between 10 and 50microns.

Upon forming the sacrificial layer 24, a structural layer 26 is formedon the sacrificial layer 24, as illustrated in FIG. 1C. The structurallayer 26 may be formed by chemical reaction, for example by oxidation,or by coating, for example with chemical vapor deposition or obliqueangle physical vapor deposition. In one embodiment, the structural layer26 is formed by depositing thin metal films, electroplating, or spin onpolymer deposition. Preferably, the structural layer 26 comprises amaterial that is different from the materials contained in thesacrificial layer 24. Multiple materials may also be used to form thestructural layer 26. In one embodiment, the structural layer 26comprises at least one of many types of materials such as photoresist;SU-8; metals such as permalloy, copper, tungsten, titanium, aluminum,silver, and gold; oxides such as silicon dioxide, silicon oxide, andsilicon oxynitride; nitrides such as silicon nitride and titaniumnitride; and polymers such as poly(dimethylsiloxane) (PDMS), polyimide,parylene, and elastomers such as silicone and rubber. In one embodiment,the structural layer 26 comprises a polymer, and more preferably, anelastomer. Preferably, the polymer is formed by mixing a series ofprecursors in viscous liquid form, and then pouring the liquid over thesubstrate 20 and into the cavity 22. Excess polymer is then removedusing a moving blade, a process of which is described in more detail in“Precision Patterning of PDMS Thin Films: A New Fabrication Method andIts Applications,” by K. Ryu and C. Liu, Sixth International Symposiumon Micro Total Analysis System (mTAS), Nara, Japan, 3-7 Nov. 2002.

In one embodiment, the structural layer 26 comprises a 10:1 (v:v)mixture of PDMS—SYLGARD™ 184 Silicone Elastomer Base and SYLGARD™ 184Silicone Elastomer Curing Agent. SYLGARD™ 184 Silicone Elastomer Baseand SYLGARD™ 184 Silicone Elastomer Curing Agent may be obtained fromDow Corning Corporation (Midland, Mich.). In one embodiment, thestructural layer 26 comprises HD-4000 polyimide. HD-4000 polyimide maybe obtained from HD MicroSystems (Wilmington, Del.). The thickness ofthe structural layer 26 may vary, however, preferably, the thickness ofthe structural layer 26 is between 1 and 100 microns, and morepreferably between 10 and 50 microns. In one embodiment, the structurallayer 26 includes a tip layer 48 and a beam layer 50 on the tip layer48. Preferably, the tip layer 48 is formed in the cavity 22, and morepreferably, the tip layer 48 fills up the entire cavity 22. In oneembodiment, upon forming the tip layer 48, excess amount of the tiplayer 48 are removed using chemical-mechanical polishing, etching, or asharp blade. In one embodiment, excess amount of the tip layer 48 areremoved using a moving blade. In one embodiment, the tip layer 48comprises a 10:1 (v:v) mixture of PDMS—SYLGARD™ 184 Silicone ElastomerBase and SYLGARD™ 184 Silicone Elastomer Curing Agent. Preferably, uponforming the tip layer 48, tip layer 48 is then cured at a temperature of70° C. to 110° C. for a duration of 20 to 40 minutes. Upon forming thetip layer 48, the beam layer 50 is formed on the tip layer 48. In oneembodiment, the beam layer 50 comprises a thin layer of HD-4000polyimide that is spin coated, patterned, and cured to form thecantilever beam 28. Preferably, the tip layer 48 and the beam layer 50comprise different materials. For example, in one embodiment, the tiplayer 48 comprises a polymer while the beam layer 50 comprises a metal.In one embodiment, the tip layer 48 and the beam layer 50 comprisepolyamide. In one embodiment, the tip layer 48 comprises a metal whilethe beam layer 50 comprises a polymer, such as polyamide or parylene. Inone embodiment, the tip layer 48 comprises an elastomer and the beamlayer 50 comprises polyamide. The formation of the structural layer 26should not disrupt the substrate 20 or the sacrificial layer 24. Uponforming the structural layer 26, the structural layer 26 is patterned toform a probe 27 having a cantilever beam 28 and a tip 30, as describedabove.

Upon forming the probe 27, the sacrificial layer 24 is removed, asillustrated in FIG. 1D. Preferably, the sacrificial layer 24 is removedusing a process or material that does not harm the substrate 20 or thestructural layer 26. In one embodiment, the sacrificial layer 24 isremoved using aluminum etchant which may be obtained from TranseneCompany (Danvers, Mass.). Upon removing the sacrificial layer 24, theprobe 27 is released from the substrate 20. The substrate 20 may thenlater be reused to form additional probes 27 since the geometry of thecavity 22 is not significantly damaged. In one embodiment, upon formingthe probe 27, the tip 30 is further sharpened. Preferably, the probe 27can be formed, in accordance with the above-described method, at a lowtemperature of no greater than 120° C.

By forming the probe 27 using the above-described method, the tip 30 ofthe probe is well defined by the inverted cavity 22 and therefore theprocess of forming a sharp tip 30, or a tip 30 with a small radius ofcurvature is possible by controlling the geometry of the inverted cavity22 instead of controlling the geometry of the tip 30 itself.Additionally, since the substrate 20 can be reused, the materials costfor producing the probe 27 can be reduced. Moreover, the above-describedmethod for fabricating a probe 27 allows for a variety of materials tobe used to manufacture the probe 27 in additional to allowing the tip 30and the cantilever beam 28 to comprise different types of materials.Furthermore, since the above-described method for fabricating a probe 27involves only two layers, a sacrificial layer 24 and a structural layer26, the method is highly efficient in comparison with prior methods, andthus allows for probes 27 to be formed at lower cost.

Shown in FIGS. 2A-2E, in cross-section, are process steps for thefabrication of an SPM probes 127 in accordance with one preferredembodiment of the invention. Elements in FIGS. 2A-2E have referencenumerals increased by one hundred from those for elements in FIGS. 1A-1Dsince they refer to like elements. As illustrated in FIG. 2A, asubstrate 120 is provided wherein at least one cavity 122 is formed inthe substrate 120, and more particularly, in the top surface 121 of thesubstrate 120. The shape of the cavity 122 forms a three dimensionalgeometry that is opposite the desired shape of the tip 130.

Upon forming the cavity 122, a sacrificial layer 124 is formed on thesubstrate 120, as illustrated in FIG. 2B. Upon forming the sacrificiallayer 124, a structural layer 126 is formed on the sacrificial layer124. The structural layer 126 is different from the material containedin the sacrificial layer 124. The structural layer 126 is then patternedto form at least one probe 127 having a cantilever beam 128 and a tip130, as described above.

In one embodiment, upon patterning the structural layer 126, an adhesionisland 132 is formed on the structural layer 126, as illustrated in FIG.2C. The adhesion island 132 may be formed by depositing an adhesionlayer and then patterning the adhesion layer to form an adhesion island132. The adhesion layer comprises at least one of many types ofmaterials such as photoresist; SU-8; metals such as permalloy, copper,tungsten, titanium, aluminum, silver, and gold; oxides such as silicondioxide, silicon oxide, and silicon oxynitride; nitrides such as siliconnitride and titanium nitride; and polymers such aspoly(dimethylsiloxane) (PDMS), polyimide, parylene, and elastomers suchas silicone and rubber. Preferably, the adhesion layer has a thickness,that is the same as the height of the adhesion island 132, of between 1and 50 micrometers. A handle 134, which preferably comprises a transfersubstrate, is then formed on or placed on the adhesion island 132. Thehandle 134 is thus connected with the adhesion island 132 and the probe127. Upon forming or placing the handle 134 on the adhesion island 132,the handle 134 is then bonded to the adhesion island 132. Preferably,the adhesion island 132 is a soft polymer which can be patterned to forman adhesion island. Preferably, upon heating the adhesion island 132,the adhesion island 132 is softened to help bond the adhesion island 132to the handle 134.

The handle 134 and the adhesion island 132 may be bonded in one of manyways, such as spin on bonding using photoresist or an adhesive polymerfor adhesive bonding, which may be patterned (see for example “VOID-FREEFULL WAFER ADHESIVE BONDING” F. Niklaus, et al.); or high-temperaturebonding, for example by heating the substrates together at about 1100°C. Preferably, the bonding process does not harm the substrate 20 or theprobe 27. In one embodiment, the adhesion island 132 is bonded to thehandle 134 using low-temperature bonding at less than 100° C. Alignmentmay be achieved using alignment mark, or using features present on thesubstrate 120, the handle 134, or the adhesion island 132.

Upon forming the probe 127, which includes the handle 134, the adhesionisland 132, and the structural layer 126 which forms the beam 128 andthe tip 130, the sacrificial layer 124 is removed, as illustrated inFIG. 2E. The substrate 120 may then later be reused to form additionalprobes 127.

In one embodiment, the structural layer 126 forms a hook 125, asillustrated in FIG. 2F. Upon forming the hook 125, the adhesion island132 is formed on the hook 125, as illustrated in FIG. 2G. The hook 125is used to improve the adhesion between the adhesion island 132 and thestructural layer 126, since the area between the adhesion island 132 andthe structural layer 126 may be small in a high-density probe array.

The individual processing steps used in accordance with the presentinvention are well known to those of ordinary skill in the art, and arealso described in numerous publications and treatises, including:Encyclopedia of Chemical Technology, Volume 14 (Kirk-Othmer, 1995, pp.677-709); Semiconductor Device Fundamentals by Robert F. Pierret(Addison-Wesley, 1996); Silicon Processing for the VLSI Era by Wolf(Lattice Press, 1986, 1990, 1995, vols 1-3, respectively); and MicrochipFabrication: A Practical Guide to Semiconductor Processing by Peter VanZant (4th Edition, McGraw-Hill, 2000). In order to etch through thesubstrate, techniques such as deep ion etching may be used (also knownas the Bosch process).

The present invention also describes a method for contact printing withan SPM probe, herein know as scanning probe contact printing. The SPMprobe is formed using any one of a variety of techniques. Preferably,the SPM probe, is formed as described above. Upon forming the SPM probe,the SPM probe is then mounted onto a scanning probe microscope, such asan atomic force microscope (AFM), or a scanning tunneling microscope(STM). In one embodiment, the SPM probe is inked before being mountedonto the scanning probe microscope. In another embodiment, the SPM probeis inked upon being mounted onto the scanning probe microscope. Uponmounting the SPM probe onto the scanning probe microscope, the SPM probeis then positioned and put near a substrate, whereupon ink istransferred from the SPM probe to the substrate. The use of a scanningprobe microscope to position the SPM probe allows for a high degree ofaccuracy for aligning and positioning the SPM probe to the substrate.

FIGS. 4A-4D illustrate, in a side view, process steps for scanning probecontact printing using an SPM probe 227, in accordance with onepreferred embodiment of the invention. In one embodiment, the SPM probes227 are used in the scanning probe contact printing method to generatesub-micron patterns 68, as illustrated in FIGS. 4A-4D, and FIGS. 5-6.For example, if the tip of the probe 227 is coated with a fluid, such asan ink 60, then a surface 64 of a substrate 62, such as a substrate madeof glass, metal, silicon, or polymer, could be printed with the probes227 after they have received the fluid 60. Biological arrays maysimilarly be formed, for example by using fluids containing biologicalcompounds, such as nucleotides (RNA, DNA, or PNA), proteins (enzymes,antibodies, etc.), lipids, carbohydrates, etc. to spot a substrate, suchas glass, silicon, or polymers. The scanning probe contact printingmethod combines the advantages of contact printing and scanning probemicroscopy technologies by using a scanning probe 227 to transferchemical or biological materials onto the substrate 62.

The probe 227 can be any type of SPM probe. Preferably, the probe 227 isa probe 27, as described above. Preferably, the scanning probemicroscopy (SPM) probe 227 used in this embodiment includes anintegrated tip 230 which comprises a material that adheres to fluid 60,such as, polymers, and more specifically, elastomers, likepoly(dimethylsiloxane), silicone, rubber, and polyimide. In oneembodiment, the tip of the probe 227 comprises a silicone elastomer.Preferably, the tip 230 comprises a polyimide, such aspoly(dimethylsiloxane), since polyimides are photodefinable andgenerally commercially available with a wide range of mechanicalproperties and achievable film thicknesses. The probe 227 includes acantilever beam 228. In order to effectively move the tip 230 around toprint arbitrary patterns 68, the probe 227, and more specifically, thecantilever beam 228 of the probe 227, has to have appropriate stiffness.The force constant (k) is used as a criterion in probe design. It iscalculated using the formula for a simple fixed-free cantilever beamunder small displacement assumption: ${k = \frac{{Ewt}^{3}}{4l^{3}}},$where E is the modulus of elasticity of the material, and w, t, l arethe width, thickness, and length of the rectangular cantilever,respectively, as illustrated in FIG. 3. Preferably, the force constantfor the cantilever beam 228 is between 0.01 to 0.5 N/m, more preferablybetween 0.03 to 0.3 N/m, and most preferably between 0.04 to 0.2 N/m.

Upon forming the probe 227, the probe 227 is then mounted onto ascanning probe microscope instrument, such as an atomic force microscope(AFM) 70, as illustrated in FIG. 6. While an atomic force microscope isillustrated in FIG. 6, the probe 227 may be mounted onto any type ofscanning probe microscope, such as, but not limited to an AFM or an STM.

Upon forming the probe 227, ink 60 is attached to the tip 230 of theprobe 227, as illustrated in FIG. 4B. Attacking ink 60 to the tip 230 ofthe probe 227 is also referred to herein as inking the probe 227. Theink 60 may comprise any material which may be dispersed or dissolved ina solvent, such as, nucleic acids, proteins, and peptides. In oneembodiment, the probe 227 is inked before being mounted onto thescanning probe microscope. In another embodiment, the probe 227 is inkedupon mounting the probe 227 onto the scanning probe microscope. Theprobe 227 may be inked in a variety of ways, such as a contact inkingmethod, as described below, and other such methods. For example, in oneembodiment, the probe 227, and more specifically, the tips 230 of theprobe 227, are inked by positioning the probe 227 near or in contactwith a second probe with an already inked tip. Preferably, the secondprobe is mounted onto a scanning probe microscope for accuratepositioning. In one embodiment, the probe 227 is inked by placing theprobe 227, and preferably, by placing the tip of the probe 227, near orin contact with a well filled with ink. In one embodiment, the probe 227is inked by placing the probe 227 near or in contact with a pad thatcomprises ink. Preferably, the pad comprises PDMS.

In one embodiment, the tip 230 of the probe 227 does not form a point42, but rather, the tip 230 forms a flat surface 290 which is inked,such as flat top 54 or 254, as illustrated by tips 30 in FIGS. 3B, 3C,3D, 3E, and 8. Preferably, ink 60 is patterned onto a flat surface, suchas flat surface 90 or flat surface 290, to form an ink pattern 92, anink pattern 292, or a pattern of ink 60, as illustrated in FIGS. 3C and8. The ink 60 may be patterned onto the flat surface 290 by using asecond probe 227 attached to a scanning probe microscope. Preferably,the ink pattern 92 comprises more than one pixel 66. In one embodiment,the ink pattern 92 comprises a first and a second pixel 66, wherein thefirst pixel 66 does not come into contact with the second pixel 66, asillustrated in FIG. 3C. Upon patterning the flat surface 290 with ink60, the flat surface 290 then is placed near, or comes into contactwith, the substrate 62. In one embodiment, upon patterning the flatsurface 290 with ink 60, the flat surface 290 is placed near, or comesinto contact with, the substrate 62 a plurality of times in order tomake multiple copies of the patterned ink from the flat surface 290 ontothe substrate 62, or onto multiple substrates 62.

Upon mounting the probe 227 onto the scanning probe microscope andattaching ink to the tip 230, also know as “inking the probe,” the probe227, the probe 227 is then positioned and placed near or brought intocontact with a substrate 62, whereupon the ink 60 is transferred fromthe probe 227 to the substrate 62, as illustrated in FIGS. 4C and 4D.The substrate 62 may be any type of material, such as silicon, gold,silver, aluminum, and paper. The tip 230 is positioned using thescanning probe microscope. Preferably, the tip 230 is placed near orbrought into contact with the substrate by moving the tip 230 towardsthe substrate 62 in a first direction D₁, as generally shown by thearrow in FIG. 4C. Once the tip 230 is placed near or brought intocontact with the substrate 62, ink 60 is transferred from the tip 230 tothe substrate 62. Upon transferring ink 60 from the tip 230 to thesubstrate 62, the tip 230 is moved away from the substrate 62 in asecond direction D₂, as illustrated in FIG. 4D, creating a dot or pixel66 as illustrated in FIG. 5. The size of the pixel 66 is dependant uponthe size of the tip 230 and the amount of time the tip 230 is in contactwith or near the substrate 62. Arbitrary, connected patterns 68, such aslines or blocks, can be formed by connecting multiple pixels 66, in amethod analogous to dot-matrix printing, as illustrated in FIG. 5. Theprobe 227 is compatible with commercial scanning probe machines. Theabove-described scanning probe contact printing method combines thechemical versatility and performance advantages of contact printing withthe production flexibility and accuracy of scanning probe microscopemachines. Additionally, no mask is necessary to produce arbitrarypatterns 68. Using the above-described scanning probe contact printingmethod, nanometer registration accuracy is feasible.

Without further elaboration it is believed that on skilled in the artcan, using the preceding description, utilize the invention to itsfullest extent. The following example is merely illustrative of theinvention and is not meant to limit the scope in any way whatsoever.

EXAMPLE

The probe 227 was mounted and tested on a Thermomicroscopes AutoProbe®M5 atomic force microscope (AFM). An organic molecule, 1-octadecanethiol(ODT), was used for the fluid 60. ODT (98%) may be obtained from AldrichChemical Company (Milwaukee, Wis.). The substrate 62 was a silicon chipcoated with a 5-nm-thick chrome layer for adhesion promotion, and a30-nm-thick gold layers. Preferably, the substrate 62 is formed from asingle crystal silicon wafers ({100} orientation), which may be obtainedfrom International Wafer Service (Portola Valley, Calif.). Gold (99.99%)for the gold layers may be obtained from Pure Tech (Brewster, N.Y.). Achromium evaporation source (chrome plated tungsten rod) to form thechrome layer may be obtained from R. D. Mathis Company (Long Beach,Calif.). A contact inking method, as described in “Contact-Inking Stampsfor Microcontact Printing of Alkanethiols on Gold”, by L. Libioulle, A.Bietsch, H. Schmid, B. Michel, and E Delamarche, Langmuir, 1999, 15, pp.300-304, was used to ink the tip 230 of the probe 227 with ODT. The tip230 comprises PDMS. A fluid pad, from which the tip 230 was to receivedthe fluid 60, was first prepared by immersing a PDMS piece (4 mm*4mm*0.3 mm) in 3 mM ethanolic ODT solution for at least 12 hours. Afterthe fluid pad was impregnated with ODT solution, the fluid pad was driedin a nitrogen stream for 10 seconds. The fluid pad was then stored in asmall glass Petri dish before use.

The probe 227 was mounted on an AFM scanning head 70, as illustrated inFIG. 6. While the scanning head 70 could move in a z direction, thesample stage of the scanning head 70 could move in x and y directionsfor rough alignment. For accurate movement in the printing process, thepiezoelectric scanner 72 inside the scanning head 70 could be controlledby internal circuitry to expand or compress, moving the probe in x, y,and z directions with nanometer scale accuracy.

In our experiments, inking was first done by bringing the tip 230 intocontact with a fluid pad, preferably, for between 5 and 15 minutes, andmore preferably, for between 8 and 12 minutes. This allowed localtransfer of ODT from the fluid pad to the tip 230. The similarelasticity and surface characteristics of the fluid pad and the tip 230provided good contact at their interface, thus excessive contact forcewas not necessary. The quasi-continuous interface formed by both thePDMS surface of the fluid pad and the tip 230 also enabled homogeneoustransfer of fluid 60 from the fluid pad to the tip 230.

After the tip 230 was inked with a sufficient amount of fluid 60, inthis case ODT, the tip 230 was moved to a designated location andlowered to contact the gold surface 64 of the substrate 62 to form apixel 66. After every formation of a pixel 66, the probe 227 was liftedand moved to another location to form another pixel 66. Because of thecapillary adhesive force at the interface between the tip 230 and thesubstrate 62, upon contact, the probe 227 could be lifted up a distanceof several microns without interrupting the contact and fluid transferbetween the tip 230 and the substrate 62. Hence contact printing couldbe conducted with even no or negative contact force between the tip 230and the substrate 62. In our experiments, all contact printings wereconducted with a contact force (F) between −200 nN to 200 nN. Pleasenote that the contact force readings of between −200 nN to 200 nN maynot be the actual contact force, however this is just representative ofthe contact force. As defined herein, the contact force (F) ortip-substrate interaction force is the z (vertical) component of theforce exerted on the probe tip 230 when the tip 230 is in contact withthe substrate 62. When the tip 230 is lowered to just contact with thesubstrate 62 without any overdrive, the contact force (F) is assumed tobe 0. Further lowering the probe handle (overdrive) will cause arepulsive force (+z direction) exerted on the tip 230 by the substrate62. If the probe handle 134 is withdrawn for a small distance, theadhesive force at interface between the tip 230 and the substrate 62will try to hold the tip 230 down on the substrate 62, thus exerting apulling (attractive) force (−z direction) on the tip 230. In both cases,the magnitude of the contact force (F) can be estimated as F=kΔz undersmall displacement assumption, where k is the force constant of thecantilever and Δz equals to the small displacement of probe handle 134.

The feature size of tip-based contact printing is affected by severalfactors, including the tip geometry, the tip-substrate, the contacttime, the relative humidity of environment, and other such parameters.With other parameters set, the printed pattern size of the pixel 66 isproportional to the contact time of the tip 230. As an example, FIGS.7A-7C show lateral force microscopy (LFM) images of 3*3 arrays of pixels66 generated using the above described SP-μCP method. The printing probetip 230 has a flat top 254 of 1.5 μm*1.5 μm, as shown in FIG. 8. Thesize of each image shown in FIGS. 7A-7C is 12 um*12 μm. The tip 230 ofthe probe 227 used to create the pixels 66 in FIGS. 7A-7C has a flat top254 of 1.5 μm*1.5 μm, as illustrated in FIG. 8. By comparison, we seethat the feature size increases as the tip-substrate contact time isincreased from FIG. 7A to FIG. 7C. For the image shown in FIG. 7A, thecontact time between the substrate 62 and the tip 230 was approximately5 seconds and the diameter D of the pixel was 1.8 μm. For the imageshown in FIG. 7B, the contact time between the substrate 62 and the tip230 was approximately 10 seconds and the diameter D of the pixel was 2.1μm. For the image shown in FIG. 7C, the contact time between thesubstrate 62 and the tip 230 was approximately 20 seconds and thediameter D of the pixel was 2.4 μm. The environment temperature used tocreate the pixels 66 shown in FIGS. 7A-7C was 21° C., and the relativehumidity was 27%.

FIG. 9 shows the diameter of pixels 66 printed from ODT by a sharp tip230 with varying contact time between the substrate 62 and the tip 230.A generally linear relationship between the diameter of a pixel 66 andthe contact time between the substrate 62 and the tip 230 can beobserved. The environment temperature used to create the pixels 66charted in FIG. 9 was 25° C., and the relative humidity was 55%. The tip230 of the probe 227 used to create the pixels 66 charted in FIG. 9 hasa radius of curvature R of 300 nm.

Lines and other complicated patterns 68 could be formed by placingpixels 66 close to each other. FIG. 10 shows an LFM image of twopatterns 68, each forming lines with a length L of 10 μm. The size ofthe image shown in FIG. 10 is 30 um*30 μm. The width W of the linesformed in FIG. 10 is 890 nm. Each line comprises 20 pixels 66. Thecontact time between the substrate 62 and the tip 230 for forming eachpixel 66 in FIG. 10 was 60 seconds. The distance between each pixel 66in FIG. 10 is 500 nm. The environment temperature used to create thepixels 66 shown in FIG. 10 was 25° C., and the relative humidity was55%. The tip 230 of the probe 227 used to create the pixels 66 shown inFIG. 10 has a radius of curvature R of 300 nm.

Comparison results of lines generated with different contact timebetween the substrate 62 and the tip 230 are shown in FIGS. 11A-11D. Thesize of the image shown in FIGS. 11A-11D is 6 um*6 μm. Each linecomprises 20 pixels 66 with a distance between adjacent pixels 66 of 500nm. The environment temperature used to create the pixels 66 shown inFIGS. 11A-11D was 25° C., and the relative humidity was 55%. The tip 230of the probe 227 used to create the pixels 66 shown in FIGS. 11A-11D hasa radius of curvature R of 300 nm. In FIG. 11A, a pattern 68 in theshape of a line was formed with a contact time between the substrate 62and the tip 230 of 10 seconds because the size of each pixel 66 wassmaller than the distance between adjacent pixels 66. The width W of theline formed in FIG. 11A is 305 nm. In FIG. 11B the contact time betweenthe substrate 62 and the tip 230 to form each pixel 66 was 20 secondsand the width of the line formed is 434 nm. In FIG. 11C the contact timebetween the substrate 62 and the tip 230 to form each pixel 66 was 30seconds and the width of the line formed is 480 nm. In FIG. 11D thecontact time between the substrate 62 and the tip 230 to form each pixel66 was 60 seconds and the width of the line formed is 890 nm. Byadjusting contact time between the substrate 62 and the tip 230 and thedistance between adjacent pixels 66, a line having a width W of lessthan 500 nm or even less than 300 nm can be achieved. In one embodiment,the width W of the formed line is approximately equivalent to thediameter D of a pixel 66, as illustrated in FIG. 11A.

In the above-described scanning probe contact printing method, theamount of interaction force and lateral friction between the tip 230 andthe substrate 62 have also reduced the amount of wear to the tip 230.The PDMS tip 230 used in the experiments showed no apparent change ofcurvature radius after more than 24 hours of the scanning probe contactprinting method. In addition, the scanning probe contact printing methodalso proved an efficient method to fill the tip 230 with sufficient ink.Additionally, a cleanroom environment should improve the quality of thepatterns 68 formed by the above-described scanning probe contactprinting method.

Numerous additional variations in the presently preferred embodimentsillustrated herein will be determined by one of ordinary skill in theart, and remain within the scope of the appended claims and theirequivalents. For example, while the examples provided above relate tosilicon-based semiconductor substrates, it is contemplated thatalternative semiconductor materials can likewise be employed inaccordance with the present invention, and that the semiconductorsubstrates may be undoped, P-doped, or N-doped. Suitable materials forthe substrates include but are not limited to silicon, gallium arsenide,germanium, gallium nitride, aluminum phosphide, Si1-xGex and AlxGa1-xAsalloys, wherein x is greater than or equal to zero and less than orequal to one, the like, and combinations thereof. Additional examples ofmaterials for use, methods, and terms used in accordance with thepresent invention are set forth in the following references:“Semiconductor Device Fundamentals” by Robert F. Pierret, p. 4, Table1.1, Addison-Wesley, 1996; “Soft Lithography and Microfabrication,” byC. Brittain, K. Paul, and G. Whitesides, Physics World 1998, 11, 31-36;“Patterning Self-Assembled Monolayers: Applications in MaterialsScience,” by A. Kumar, H. A. Biebuyck, and G. M. Whitesides, Langmuir,1994, 10, pp. 1498-1511; “Fabrication and Imaging of Two-DimensionalPatterns of Proteins Adsorbed on Self-Assembled Monolayers by ScanningElectron Microscopy”, by G. P. Lopez, H. A. Biebuyck, R. Harter, A.Kumar, and G. M. Whitesides, Journal of the American Chemical Society,1993, 115, pp. 10774-10781; “Micro-Stamp Patterns of Biomolecules forHigh-Resolution Neuronal Networks,” by D. W. Branch, J. M. Corey, J. A.Weyhenmeyer, G. J. Brewer, and B. C. Wheeler, Medical and BiologicalEngineering and Computing, vol. 36, pg. 135-141; “Patterning of aPolysiloxane Precursor to Silicate Glasses by Microcontact Printing,” byC. Marzolin, A. Terfort, J. Tien, and G. Whitesides, Thin Solid Films,1998, 315, 9-12; “Soft Lithography”, by Y. Xia and G. M. Whitesides,Annual Review of Material Science, 1998, 28, pp. 153-84; “PrecisionPatterning of PDMS Thin Films: A New Fabrication Method and ItsApplications,” by K. Ryu, C. Liu, 6th International Symposium on MicroTotal Analysis System (μTAS), Nara, Japan, 2002; and “Contact-InkingStamps for Microcontact Printing of Alkanethiols on Gold,” by L.Libioulle, A. Bietsch, H. Schmid, B. Michel, and E Delamarche, Langmuir,1999, 15, pp. 300-304.

Although the invention has been described and illustrated with referenceto specific illustrative embodiments thereof, it is not intended thatthe invention be limited to those illustrative embodiments. Thoseskilled in the art will recognize that variations and modifications canbe made without departing from the spirit of the invention.

1. A method for fabricating a scanning probe microscope probe,comprising: forming a structural layer on a substrate, wherein thesubstrate forms a cavity, and a sacrificial layer is located between thesubstrate and the structural layer; forming an adhesion layer on thestructural layer; forming a handle on the adhesion layer; selectivelyremoving the sacrificial layer; and releasing the structural layer fromthe substrate.
 2. The method of claim 1, wherein the structural layerforms a probe having a tip and a cantilever beam connected with the tip.3. The method of claim 1, wherein the cavity forms a pyramid.
 4. Themethod of claim 1, wherein the cavity forms a bottom, and the bottom isgenerally flat.
 5. The method of claim 1, wherein the structural layerincludes a tip layer in the cavity and a beam layer on the tip layer. 6.The method of claim 5, wherein the tip layer comprises an elastomer. 7.The method of claim 5, wherein the tip layer comprises a first materialand the beam layer comprises a second material, wherein the firstmaterial is different from the second material.
 8. The method of claim1, wherein the sacrificial layer comprises one of a metal, an oxide, anda polymer.
 9. A method for fabricating a scanning probe microscopeprobe, comprising: forming a structural layer on a substrate, thestructural layer having a tip layer and a beam layer, where the tiplayer comprises a first material and the beam layer comprises a secondmaterial, the first and second materials are independently selected fromthe group consisting of metals, oxides, polymers, elastomers, andcombinations thereof, the first material is a different material fromthe second material, the substrate forms a cavity, the tip layer is inthe cavity, the beam layer is on the tip layer and a sacrificial layeris located between the substrate and the structural layer; patterningthe structural layer; selectively removing the sacrificial layer; andreleasing the structural layer from the substrate.
 10. The method ofclaim 9, wherein the tip layer comprises one of a metal, an oxide, and apolymer.
 11. The method of claim 9 further comprising forming anadhesion island on the structural layer.
 12. The method of claim 11further comprising placing a handle on the adhesion island.
 13. Themethod of claim 12, wherein the adhesion island is bonded with thehandle and the structural layer.
 14. A scanning probe microscope probeformed by the method of claim
 1. 15. A scanning probe microscope probeformed by the method of claim
 9. 16. The method of claim 9 furthercomprising sharpening the tip.
 17. A scanning probe microscope probecomprising: a tip comprising a first material; and a cantilever beamconnected with the tip, the cantilever beam comprising a secondmaterial, where the first material is selected from the group consistingof oxides, polymers, elastomers, and combinations thereof, the secondmaterial is selected from the group consisting of metals, oxides,polymers, elastomers, and combinations thereof, and the first materialis a different material from the second material.
 18. The scanning probemicroscope probe of claim 17, wherein the tip has a height of between 1and 10 microns.
 19. The scanning probe microscope probe of claim 17,wherein the cantilever beam has a length of between 100 and 1000microns.
 20. The scanning probe microscope probe of claim 17 furthercomprising an adhesion island connected with the cantilever beam. 21.The scanning probe microscope probe of claim 20 further comprising ahandle connected with the adhesion island.
 22. The scanning probemicroscope probe of claim 17, where the first material comprises anelastomer.
 23. A method for fabricating a scanning probe microscopeprobe, comprising: forming a structural layer on a substrate, thestructural layer having a tip layer and a beam layer, where the tiplayer comprises a first material and the beam layer comprises a secondmaterial, the first and second materials are the same and are selectedfrom the group consisting of oxides, nitrides, elastomers,poly(dimethylsiloxanes), polyimides, parylenes, and combinationsthereof, the substrate forms a cavity, the tip layer is in the cavity,the beam layer is on the tip layer, and a sacrificial layer is locatedbetween the substrate and the structural layer; patterning thestructural layer; selectively removing the sacrificial layer; andreleasing the structural layer from the substrate.
 24. The method ofclaim 9, where the tip layer comprises an elastomer.
 25. A scanningprobe microscope probe comprising: a tip comprising a first material;and a cantilever beam connected with the tip, the cantilever beamcomprising a second material, where the first and second materials arethe same and are selected from the group consisting of oxides, nitrides,elastomers, poly(dimethylsiloxanes), polyimides, parylenes, andcombinations thereof.
 26. The scanning probe microscope probe of claim17, where the first material is selected from the group consisting ofoxides, nitrides, elastomers, poly(dimethylsiloxanes), polyimides,parylenes, and combinations thereof.
 27. The scanning probe microscopeprobe of claim 9, where the first material is selected from the groupconsisting of oxides, nitrides, elastomers, poly(dimethyisiloxanes),polyimides, parylenes, and combinations thereof.
 28. The method of claim1, where the adhesion layer conforms to a hook integral to thestructural layer.
 29. The method of claim 1, where the material of theadhesion layer is selected from the group consisting of oxides,nitrides, elastomers, poly(dimethylsiloxanes), polyi mides, parylenes,and combinations thereof.